How do I create a radial metallic gear material procedurally?
Here I'm converting Generated Coordinates to something like Object Coordinates so this should work on any size of gear.
A Gradient Texture set to Radial gives us this output.

If we feed this into a Noise Texture we get this.

We can mix in a bit of the regular coordinate space to give some irregularity.

And here I've used this output to drive the base color between two shades of brown, the roughness, and a Bump Node.  I've also used a bit of regular ol' anisotropy.

And since these are generated coordinates based on a bounding box around your mesh, you can easily use this on any size of gear.